Ignition system for gas burners



Jan. 17, 1967 SHIGERU TEZUKA ETAL 9 IGNITION SYSTEM FOR GAS BURNERS Filed July 26, 1965 3 She ts-Sheet 1 Jam 1 1967 v SHIGERU' TEZUKA ETAL 3,298,421

I IGNITION SYSTEM FOR GAS BURNERS Filed July 26, 1965 s Sheets-Sheet 2 I 1967 SHIGERU TEZUKA ETAL 1 I IGNITION SYSTEM FOR GAS BURNERS Filed July 26, 1965 1 3 Sheets-Sheet 1S United States Patent ()flice 3,298,421 Patented Jan. 17, 1967 3,298,421 IGNITIQN SYSTEM FUR GAS BURNERS Shigeru Tezuka and Kazurna Suzuki, Kokuhunji-shi, To-

kyo, Japan, assignors to Rion Company, Limited, To-

kyo, Japan, a corporation of Japan Filed July 26, 1965, Ser. No. 474,853 Ciaims priority, application Japan, Sept. 28, 1954, 39/759 19, 39/753511 2 tjlairns. (Cl. 158-125) This invention relates to ignition systems for gas burners wherein piezoelectric elements are used.

In the conventional gas lighter, the gas is ignited by the friction between the flint and file but the wear of the flint is much. A method of directly igniting the gas by heating a resistance wire with a dry cell as an electric source has been adopted in gas ranges, instantaneous boilers and table gas lighters but has a defect that the consumption of dry cells and the damage of resistance wires are high. In order to eliminate the above mentioned detect, the present invention is to provide a device adapted specifically for the above mentioned gas burner in an ignition system utilizing a spark by a high voltage generated by applying an impact to a piezoelectric element. It is necessary for such piezoelectric ignition system that the hammering direction of a hammer for the piezoelectric element should coincide with the axis of the piezoelectric element so that the piezoelectric element may be prevented from breaking and the efliciency of generating a high pressure may not be reduced.

It is also desirable that no part of the mechanism will be much worn by repeated uses. It is further desirable that the device can be easily fitted to and set in a gas burner of any shape.

A principal object of the present invention is to make the operation of a trigger smooth by utilizing a skipping motion. That is to say, as passing through an unstable point plays a part of pulling the trigger, when it is used, no other mechanism will be required, therefore a motion will be accurately given to the hammer and there will be an effect of preventing the damage and wear of the mechanism part.

Another object of the present invention is to provide an ignition system which is simple in the mechanism, has few parts to be worn and can be used for a long time.

A further object of the present invention is to generate a high voltage by giving a linear motion to a hammer in the axial direction of a piezoelectric element formed in the form of a column and to prevent the piezoelectric element from breaking.

Another object of the present invention is to provide an ignition system which can automatically effect a spark discharge ignition synchronized with the opening operation of a fuel valve of a burner.

The present invention shall now be explained with reference to the accompanying drawings in which:

FIGURE 1 is an elevation of an ignition system of the present invention with the essential part sectioned;

FIGURE 2 is a view showing the operating state;

FIGURE 3 illustrates another embodiment of the invention;

FIGURES 4 to 6 illustrate examples as applied to domestic gas burners;

FIGURE 7 is an explanatory view showing the structure and operation of the wound spring shown in FIG- URE 1;

FIGURES 8 and 9 are explanatory views showing the structure and operation of the leaf spring in FIGURE 3, respectively.

FIGURE 1 illustrates the present invention as applied to a gas lighter. In the drawings, 1 and 2 are upper and lower cases, respectively. 3 is a nozzle to which is connected a fuel pipe 5 connected to a fuel tank 4 and electrically insulated from others. A valve 6 to be opened and closed by the operation of a lever 7 is set in the joint part of the fuel tank 4 with the fuel pipe 5. 8 is a hammer formed of a metal, provided with a pin 9, connected to and supported in the case 1 through wound springs 10 and provided as opposed to a piezoelectric element 15 so as to make a linear motion in the axial direction of said piezoelectric element 15. 11 is an operating rod provided with hooks 12 and 12' to engage with the pin 6 and a handle 13 projected out of the case and set so that, when said handle 13 is pushed with a finger, said operating rod 11 may project into the lower case 2 and may lower the lever 7 to open the valve 6 and that, when the handle 13 is released, the operating rod 11 may return to the original position due to the resiliency of a spring 14 to close the valve 6. As described later, the pin 9 and the hooks 12 and 12 are set in such relative positions that, after the operating rod 11 lowers and the hammer S strikes the piezoelectric element, when the operating rod 11 returns to the original position, the hammer 8 may also return to the original position. The piezoelectric element 15 is provided with a cap 16 on the side to be subjected to the impact and is fixed to the bottom of the case 1. The signs and noted on the piezoelectric element 15 in the drawing represent polarities. The piezoelectric element is electrically connected in parallel. Said piezoelectric element 15 is connected at one terminal to the nozzle 3 insulated from the case with an insulator 18 through an insulated lead wire 17 and at the other terminal to an electrode 21 provided opposite the nozzle 3 through the case 1 and a nozzle cover 20 through a lead wire 19. Both electrodes 3 and 21 are opposed to each other at a spacing adapted to make a spark discharge. A hole 22 to discharge a flame is made in the upper part of the nozzle cover 20. 23 is such damper as of rubber provided to prevent vibration caused by the impact from being transmitted to the lower part.

The wound spring 10 may be replaced with a leaf spring.

The igniting operation shall now be explained. First of all, in case the hammer 8 and wound spring 10 are connected with each other in such relative positions as in FIGURE 1, there will be two upper and lower resiliently stable positions for the hammer 8. In case the hammer moves from the position to the other position, it will pass through an intermediate unstable point. Therefore, if the hammer 8 is moved through the unstable point by an external force, it will quickly move to the other stable point. (This motion shall be known as a skipping motion hereinafter.) Therefore, the external force required to be ap plied to the handle 13 to give a strong impact to the piezoelectric element 15 may be very small. That is to say, when the operating rod 11 is moved up and down with the operation of the handle, the hooks 12 and 12' will engage with the pin 9 attached to the hammer 8, respectively, and a vertical skipping motion will be given to the hammer. That is to say, when not used, the operating rod 11 will be up due to the force of the spring 14. Therefore, due to the engagement of the hook 12 with the pin 9, the hammer 8 will be in the upper stable position. The state in such case is shown in FIGURE 1. Now, if the handle 13 is lowered with a finger, the hook 12' will engage with the pin 9 and then the hammer 8 will lower with the operating rod 11. When the hammer has passed through the unstable point, due to the resiliency of the wound spring 10, the hammer will quickly move to the lower stable point independently of the operating rod, will strike the piezoelectric element 15' and will be in such state as in FIGURE 2. The voltage generated in the piezoelectric element by the above mentioned impact will be led to the nozzle 3 which is a sparking terminal and the electrode 21 through the lead wire 17 and case 1 and will produce a spark discharge. With the fall of the oper-- ating rod 11, by the operative connection of the lever 7, the valve 6 will be opened and the gas will be jetted out of the nozzle 3 through the fuel pipe 5 and will be ignited by the spark discharge.

The structure and operation of the wound spring in FIGURE 1 shall be detailed. In FIGURE 7, the wound spring 10 is made by Winding at least once a linear spring material in the middle part and is connected at one end to the case 1 and at the other end of the hammer 8 as in B. As the hammer S is moved downward, the fitting point b will move to c, the spring 1t} will take the position C and will be in an unstable state. When the hammer 8 has further slightly moved downward, even if no external force is applied, the spring 10 will quickly move to the state of D and the point 0 will skip to d. At this time, the hammer will strike the piezoelectric element. In the state of C, the wound part of the wound spring will be contracted.

In the process in which the hammer passes over the unstable state and collides with the piezoelectric element in the above-mentioned operation, the impact force will be given by the deformation and resiliency of the spring members themselves, therefore no external force will be required and no force accompanying the operation of the hammer will be lost. Further, as two spring members are provided as arranged symmetrically between the hammer and the case, the force in only the direction of the motion will be given to the hammer, the components in the direction at right angles to said force will be canceled with each other, therefore there will be no frictional force on the side of the hammer, the impact operation will be smooth and efficient and no partial wear will be produced.

Further, the ignition system shown in each of the above mentioned embodiments can be used for town gas burners andoil burners in exactly the same manner.

As described above, in the present invention, the conventional defects are eliminated, the skipping motion between two stable points is utilized, therefore the operation of the system and the action of the hammer are smooth, the motions of the operating rod and the hammer areindependent of each other in hammering, therefore the mechanism is simple, the parts to be worn are few and the system can be-used semipermanently.

Further, as described above, if the motion of the hammer is deviated from the axis of the piezoelectric element, when the hammering is repeated. the piezoelectric element will break. However, as the present invention is formed as mentioned above, the hammer can be prevented from breaking.

FIGURES 3 to 6 show an embodiment as applied to a gas burner so as to make a spark ignition as synchronized with the opening and closing operation of a fuel opening and closing valve. Usually, in a gas burner, the igniting operation is different from that of a cigarette lighter and it is customary that the artificial operation consists mostly of a fuel valve opening and closing operation. The present invention is distinguished in that a spark will be automatically generated to ignite the fuel at the time of this conventional operation.

FIGURE 3 illustrates a generating part P of the system of the present invention. In the drawing, 28 is a case, 29 is a piezoelectric element and 34} is a hammer. 31 and 31 are leaf springs. 32 is an operating rod. 33 and 33' are hooks. 34 is a pin. 35 and 35' are holes made at the respective ends of the case. In FIGURE 4, 36 is a fuel valve, 37 is a rotary shaft, 38 is a lever and 39 is a rotary grip. A columnar piezoelectric element 29 is fixed to one ened of the interior of the case 28 and a hammer 30 having a proper weight is provided coaxially with and oppositely to the piezoelectric element 29 so as to be movable 4 in the axial direction. The hammer 3t) is connected to and supported in the case 28 through the curved leaf springs 31 and 31' is set in parallel with the above mentioned axial direction and is provided with a pin 34 to engage with the hooks 33 and 33' provided on the operating rod 32 to engage with the lever 38 fixed to the rotary shaft 37 of the valve 36 of the fuel pipe. In response to the rightward and leftward movement of the operating rod 32 as operatively connected with the rotation of the rotary grip 39 of the valve 36, with the engagement of the pin 34 with the hooks 33 and 33', the hammer 30 will move to the right and left, respectively. Two stable points are given on the right and left to the hammer 30 by the leaf springs 31 and 31 and the manner of the movement of the hammer will be a skipping motion between the two stable points. Therefore, due to this skipping motion, the hammer 30 will strike the piezoelectric element 29 with a large impact force. In the structure, the operating rod 32 is projected to the right and left through the holes 35 and 35' made in both wells of the case 2%, respectively, and can be connected to the generating part P when the valve 26 is located on either of the right and left sides. The connection of the lever 38 with the operating rod 32 will be as in FIGURE 5 when the generating part P is located to the left of the valve 36 and will be as in FIGURE 8 when said part P is located to the right. Usually, when the rotary grip 39 is rotated anticlockwise, the valve 36 will be opened. Therefore, in FIGURES 5 and 6, the lever 38 can be so set that, when it rotates anticlockwise, the operating rod 32 may be move rightward to disengage the hammer 34 from the first stable point and to give it a skipping motion.

As described above, the gas burner igniting apparatus of the present invention has an advantage that, as a spark ignition can be automatically made by generating a high voltage in the generating part as synchronized with the opening operation of the valve and the impact operation of the hammer for the piezoelectric element is caused by the skipping motion between two stable points given by the two spring members, the burner can be ignited very smoothly without any friction and scratching action and without any loss of the force.

The structure and operation of the leaf spring 31 in FIGURE 3 shall be explained. In FIGURES 8 and 9, the leaf spring is curved as in A and is connected at one end to the case and at the other end to the hammer 30 as in B. When the hammer 30 is moved downward, the spring will be disengaged from the stable point of B and will be at C. When said point C is slightly passed, the spring itself will skip to the second stable point D.

As described above, the present invention is simple in structure and assembly; it can be easily adapted to burners of any type, and is so reasonable in the operation and action as to be able to safely and positively ignite the gaseous fuel ejected from the burner.

What is claimed is: 1. An ignition system for a gas burner comprising a columnar piezoelectric element mounted in a case;

a hammer arranged on the axial line of said piezoelectric element so as to strike said piezoelectric element;

an operating rod to contribute to the forward and backward motions of said hammer, said rod being mounted in guides so as to reciprocate on an axis parallel to the axial line of the hammer and having means to reciprocate the rod including lost motion connecting means between the rod and the hammer; and

two spring members symmetrically engaged between both sides of said hammer and said case pivotally at inner-side ends thereof with said hammer and at outer-side ends thereof with said case, respectively, in such manner, that said hammer is provided with an overcenter skipping motion,

each of said spring members urging said hammer into one of two stable points at both sides of a dead center position, whereby said overcenter skipping motion is imparted to said hammer through an actuation of said operating rod and an impact force is given to said piezoelectric element. 2. An apparatus for automatically igniting the gaseous fuel of a gas burner, comprising a columnar piezoelectric element mounted in a case;

a hammer arranged on the axial line of said piezoelectric element so as to strike said piezoelectric element;

an operating rod to contribute to the forward and backward motion of said hammer, said rod being mounted in guides so as to reciprocate on an axis parallel to the axial line of the hammer and having means to reciprocate the rod including lost motion connecting means between the rod and the hammer;

two spring members symmetrically engaged between both sides of said hammer and said case pivotally at inner-side ends thereof with said hammer and at outer-side ends thereof with said case, respectively, in such manner that said hammer is provided with an overcenter skipping motion;

a rotary shaft connected with a fuel valve of said gas burner and contributing to opening and closing operations of said valve; and

a lever fixed to said rotary shaft,

said operating rod being connected at its one end with said hammer andvat the other end with said lever, and being adapted to urge said hammer into one of two stable points at both sides of a dead center position, whereby said o-vercenter skipping motion is imparted to said hammer through an actuation of said operating rod synchronized with the opening operation of said fuel valve and an impact force is given to said piezoelectric element.

References Cited by the Examiner UNITED STATES PATENTS 3,096,811 7/1963 Gustafson 158-28 3,136,355 6/1964 Weber 15828 X 3,200,295 8/ 1965 Owens et a1 67-7 X JAMES W. WESTHAVER, Primaly Examiner. 

1. AN IGNITION SYSTEM FOR A GAS BURNER COMPRISING A COLUMNAR PIEZOELECTRIC ELEMENT MOUNTED IN A CASE; A HAMMER ARRANGED ON THE AXIAL LINE OF SAID PIEZOELECTRIC ELEMENT SO AS TO STRIKE SAID PIEZOELECTRIC ELEMENT; AN OPERATING ROD TO CONTRIBUTE TO THE FORWARD AND BACKWARD MOTIONS OF SAID HAMMER, SAID ROD BEING MOUNTED IN GUIDES SO AS TO RECIPROCATE ON AN AXIS PARALLEL TO THE AXIAL LINE OF THE HAMMER AND HAVING MEANS TO RECIPROCATE THE ROD INCLUDING LOST MOTION CONNECTING MEANS BETWEEN THE ROD AND THE HAMMER; AND TWO SPRING MEMBERS SYMMETRICALLY ENGAGED BETWEEN BOTH SIDES OF SAID HAMMER AND SAID CASE PIVOTALLY AT INNER-SIDE ENDS THEREOF WITH SAID HAMMER AND AT OUTER-SIDE ENDS THEREOF WITH SAID CASE, RESPECTIVELY, IN SUCH MANNER, THAT SAID HAMMER IS PROVIDED WITH AN OVERCENTER SKIPPING MOTION, EACH OF SAID SPRING MEMBERS URGING SAID HAMMER INTO ONE OF TWO STABLE POINTS AT BOTH SIDES OF A DEAD CENTER POSITION, WHEREBY SAID OVERCENTER SKIPPING MOTION IS IMPARTED TO SAID HAMMER THROUGH AN ACTUATION OF SAID OPERATING ROD AND AN IMPACT FORCE IS GIVEN TO SAID PIEZOELECTRIC ELEMENT. 